cue modules: move stdlib to pkg/alpha.dagger.io

In preparation for Europa, we will vendor multiple CUE modules:

- `pkg/alpha.dagger.io`: legacy non-europa packages
- `pkg/dagger.io`: core Europa packages
- `pkg/universe.dagger.io`: Europa universe

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

pkg/alpha.dagger.io/kubernetes/kubernetes.cue

@@ -0,0 +1,132 @@
+// Kubernetes client operations
+package kubernetes
+
+import (
+	"alpha.dagger.io/dagger/op"
+	"alpha.dagger.io/dagger"
+	"alpha.dagger.io/alpine"
+)
+
+// Kubectl client
+#Kubectl: {
+
+	// Kubectl version
+	version: dagger.#Input & {*"v1.19.9" | string}
+
+	#code: #"""
+		[ -e /usr/local/bin/kubectl ] || {
+			curl -sfL https://dl.k8s.io/${KUBECTL_VERSION}/bin/linux/amd64/kubectl -o /usr/local/bin/kubectl \
+			&& chmod +x /usr/local/bin/kubectl
+		}
+		"""#
+
+	#up: [
+		op.#Load & {
+			from: alpine.#Image & {
+				package: bash: true
+				package: jq:   true
+				package: curl: true
+			}
+		},
+		op.#WriteFile & {
+			dest:    "/entrypoint.sh"
+			content: #code
+		},
+		op.#Exec & {
+			args: [
+				"/bin/bash",
+				"--noprofile",
+				"--norc",
+				"-eo",
+				"pipefail",
+				"/entrypoint.sh",
+			]
+			env: KUBECTL_VERSION: version
+		},
+	]
+}
+
+// Apply Kubernetes resources
+#Resources: {
+
+	// Kubernetes config to deploy
+	source: dagger.#Input & {*null | dagger.#Artifact}
+
+	// Kubernetes manifest to deploy inlined in a string
+	manifest: dagger.#Input & {*null | string}
+
+	// Kubernetes manifest url to deploy remote configuration
+	url: dagger.#Input & {*null | string}
+
+	// Kubernetes Namespace to deploy to
+	namespace: dagger.#Input & {*"default" | string}
+
+	// Version of kubectl client
+	version: dagger.#Input & {*"v1.19.9" | string}
+
+	// Kube config file
+	kubeconfig: dagger.#Input & {string | dagger.#Secret}
+
+	#code: #"""
+		kubectl create namespace "$KUBE_NAMESPACE"  > /dev/null 2>&1 || true
+
+		if [ -d /source ] || [ -f /source ]; then
+			kubectl --namespace "$KUBE_NAMESPACE" apply -R -f /source
+			exit 0
+		fi
+
+		if [ -n "$DEPLOYMENT_URL" ]; then
+			kubectl --namespace "$KUBE_NAMESPACE" apply -R -f "$DEPLOYMENT_URL"
+			exit 0
+		fi
+		"""#
+
+	#up: [
+		op.#Load & {
+			from: #Kubectl & {"version": version}
+		},
+		op.#WriteFile & {
+			dest:    "/entrypoint.sh"
+			content: #code
+		},
+
+		if (kubeconfig & string) != _|_ {
+			op.#WriteFile & {
+				dest:    "/kubeconfig"
+				content: kubeconfig
+				mode:    0o600
+			}
+		},
+
+		if manifest != null {
+			op.#WriteFile & {
+				dest:    "/source"
+				content: manifest
+			}
+		},
+		op.#Exec & {
+			always: true
+			args: [
+				"/bin/bash",
+				"--noprofile",
+				"--norc",
+				"-eo",
+				"pipefail",
+				"/entrypoint.sh",
+			]
+			env: {
+				KUBECONFIG:     "/kubeconfig"
+				KUBE_NAMESPACE: namespace
+				if url != null {
+					DEPLOYMENT_URL: url
+				}
+			}
+			if manifest == null && source != null {
+				mount: "/source": from: source
+			}
+			if (kubeconfig & dagger.#Secret) != _|_ {
+				mount: "/kubeconfig": secret: kubeconfig
+			}
+		},
+	]
+}